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Home/Secretary of State directory/Series LLC/Illinois Series LLC: one entity, many protected series
Illinois . Series LLC available

Illinois Series LLC: one entity, many protected series.

Illinois statutorily authorizes the Series LLC . a master LLC that contains multiple internal series, each with its own assets, liabilities, members, and managers. Properly maintained, each series is liability-protected from the others. Common in real estate, fund management, and multi-brand operating businesses.

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When an Illinois Series LLC makes sense

  • Real estate portfolios. Each property held in its own series. Liability on Property A does not reach Property B.
  • Fund management. Multiple investment vehicles under one umbrella.
  • Multi-brand businesses. Distinct brand lines isolated from each other.
  • Family wealth structures. Different beneficiaries assigned to different series.
  • Cost efficiency. One formation fee, one annual report (in most cases), many separated risk pools.
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Guide

Series LLC by state

The national explainer above this page: what changes between jurisdictions, and why.

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Secretary of State directory

Every filing the state business office takes, state by state.

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Illinois business filings

Every filing a business makes in Illinois, gathered on one page.

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Professional LLC and PC in Illinois

Professional LLC and PC, state by state

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Federal EIN in Illinois

The federal EIN, state by state

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Secretary of State in Illinois

The Secretary of State, state by state

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S-Corp Election in Illinois

The S-Corp election, state by state

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Multi-cell structure

Illinois Series LLC: at a glance.

Single parent LLC with separate liability-protected series. Only available in some states.

Filing details

How Illinois handles Series LLC.

Illinois Business SearchLook up any Illinois entity and read every status right.
Where to fileSecretary of State office, online portal, or by mail with the required fee.
TurnaroundStandard processing: 5-10 business days. Expedited service available for an additional state fee.
Required informationEntity name + ID, current officers and registered agent, principal office address.
Common pitfallsMismatched officer addresses, expired registered agent, missed prior reports causing administrative dissolution.
Frequently asked

Illinois Series LLC questions.

Does the Illinois Secretary of State allow series LLCs?

Only if Illinois's LLC act authorizes them, which not all states do. Where Illinois allows it, you file one certificate that lets the LLC create protected series inside it; where it does not, you form in a series-friendly state and register in Illinois as a foreign LLC. We confirm Illinois's exact status before you build on a series structure.

How do I file a series LLC with Illinois?

In a series state, you file a certificate of formation with the specific series language Illinois requires, then document each series internally under the master Operating Agreement rather than filing each with the SOS. We prepare the correct Illinois series certificate and the master agreement that makes the shield real.

How is an Illinois series LLC taxed?

Federal treatment is still developing; many owners file per series while others report under the parent, and Illinois may follow federal or apply its own rule. We flag the current Illinois and IRS treatment and obtain each series its EIN where its activity requires one.

Is a series LLC cheaper than multiple LLCs in Illinois?

Usually: you pay one Illinois formation fee for the parent rather than a fee per series, though some states add a per-series charge, and the bigger cost is disciplined record-keeping. Current Illinois figures and our service pricing are on the pricing page.

Can I convert my regular Illinois LLC to a series LLC?

Often yes where Illinois allows series, by amending the certificate and Operating Agreement to authorize series. It is not automatic; opening sub-accounts does not create a series. We handle the Illinois amendment and rebuild the agreement so the shield is actually in place.

Is a series LLC the same as a holding company?

No: a holding structure owns separate subsidiary LLCs each with its own filing, while a series LLC keeps them inside one entity as series. The holding route is more widely respected across states; the series LLC is cheaper. We help you weigh which fits Illinois and where you operate.

Can File.Business form an Illinois series LLC?

Yes. We confirm Illinois authorizes series, file the correct certificate with the required series language, build the master Operating Agreement, and set up EINs and records per series, so the structure is legally real rather than just sub-accounts under one name.

Related

Related services

Illinois Secretary of StateOverview, contact, full filing index. Annual reportDue dates, fees, and how to file. Registered agentRequirements and renewal. Compliance calendarEvery deadline that touches your entity.

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